This is a mechanical heart I designed using the HUEFORGE software. It's perfect as a gift or to decorate your room.

Please print with a layer height of 0.08 mm. The file also includes the .amf files of all color changes, but there are some instructions here as well:

Exchange instructions:
Starting with black
Change it to dark gray on the 5th layer
Change it to light gray on the 9th layer
Change to white on the 14th layer